Within the scope of the vehicle dynamics regulation of a motor vehicle, a dynamic brake regulating system may be used for stabilizing the vehicle motion in which a targeted and selective brake intervention may be executed on each wheel by individually predetermining a brake pressure for each wheel. Such a brake regulating system for a passenger vehicle, as is described in German Patent Application No. 39 19 347, includes a central control unit, which when needed, e.g., when instability of the driving condition begins or is already occurring, determines an individual brake pressure for each wheel from a number of specific input variables for the particular driving situation.
The control unit subsequently transmits a manipulated variable for the brake pressure of the particular wheel to a modulator assigned to that wheel; the modulator in turn acts on the brake system, which is normally a hydraulic brake system, setting the brake pressure, required for stabilizing the driving situation, at the particular wheel. In addition or alternatively to providing the manipulated variables for the brake pressures of the wheels, the control unit may also determine a manipulated variable for reducing an output variable of the vehicle drive, e.g., the engine torque, so that, via targeted reduction of the driving power, a stabilization of the driving situation may be effected or at least supported.
Measured data regarding the wheel speeds, the yaw rate of the vehicle, and the steering wheel angle representing the driver's intention, is supplied as input variables to the control unit of the brake regulating system described in German Patent Application No. 39 19 347. A measured yaw rate of the vehicle corresponding to an actual state is then determined in the control unit from this data and compared to a desired yaw rate, corresponding to a setpoint state determined from the steering wheel angle. When needed, i.e., in the case of a discrepancy between actual state and setpoint state, manipulated variables for individual brake pressures of the wheels are determined from the degree of the discrepancy and passed on to the modulators assigned to the particular wheels.
In contrast to a passenger vehicle, a higher number of degrees of freedom of movement have to be taken into account in the vehicle dynamics regulation of commercial vehicles. Due to the comparatively higher center of gravity, tilting motions or rolling motions of the vehicle body may occur, for example. Therefore, for reliably stabilizing the vehicle motion when used in a commercial vehicle, the brake regulating system described in German Patent Application 39 19 347 is only conditionally suitable.